POEMS syndrome with undetectable M-protein: a case report and literature review.

BACKGROUND: Polyneuropathy, organomegaly, endocrinopathy, M-protein, and skin changes (POEMS) syndrome is a rare plasma cell (PC) neoplasm with associated paraneoplastic syndrome. According to the current diagnostic criteria, peripheral polyneuropathy and monoclonal PC proliferative disorder represent two mandatory criteria. CASE PRESENTATION: We report a 54-year-old male with peripheral neuropathy of bilateral lower limbs, sclerotic bone lesions, elevated vascular endothelial growth factor (VEGF) levels, splenomegaly, extravascular volume overload, endocrinopathy, and skin hemangiomas. Of note, serum and urine protein electrophoresis (PEP) and immunofixation electrophoresis (IFE) of this patient indicated undetectable M-protein and the normal ratio of free light chains κ and λ (FLC-R (κ/λ)). No monoclonal PCs were found in bone marrow examinations or biopsy of diseased bones. However, his clinical manifestations matched most of the diagnostic criteria. After excluding other diseases that are easily confused with POEMS syndrome, the diagnosis of variant POEMS syndrome with undetectable M-protein was proposed. The patient obtained clinically significant improvement and elevated VEGF returned to normal after 6 months of treatment with lenalidomide plus dexamethasone. CONCLUSIONS: Monoclonal PC dyscrasia (M-protein) while being a mandatory criterion for POEMS syndrome is undetectable in a considerable amount of patients that otherwise demonstrate typical symptoms. Here, we reported a case of variant POEMS syndrome with featured clinical manifestations, elevated VEGF levels, and good response to therapies targeting PCs but no evidence of M-protein. Therefore, negative results in M-protein and monoclonal PCs aren't enough to reject the diagnosis of POEMS syndrome. It is imperative to recognize the variant form of POEMS syndrome.

Chemotherapy plus therapeutic plasmapheresis with 4% human albumin solution in multiple myeloma patients with acute kidney injury: a prospective, open-label, proof-of-concept study.

As no unified treatment protocol or evidence yet exists for plasmapheresis without plasma, this study explored the outcomes of using 4% human albumin (ALB) solution as a replacement solution in patients undergoing plasma exchange for multiple myeloma (MM) patients with acute kidney injury (AKI). This study was prospectively registered (ChiCTR2000030640 and NCT05251896). Bortezomib-based chemotherapy plus therapeutic plasmapheresis (TPP) with 4% human ALB solution was assessed for three years in patients with MM aged >18 years, with AKI according to the Kidney Disease Improving Global Outcomes criteria, and without previous renal impairment from other causes. The primary endpoints were changes in renal function over 18 weeks and survival outcomes at 36 months. The secondary endpoints were the incidence of adverse reactions and symptom improvement. Among the 119 patients included in the analysis, 108 experienced renal reactions. The M protein (absolute changes: median -12.12%, interquartile ranges (IQRs) -18.62 to -5.626) and creatine (median -46.91 µmol/L, IQR -64.70 to -29.12) levels decreased, whereas the estimated glomerular filtration rate (eGFR) increased (median 20.66 mL/(min·1.73 m2), IQR 16.03-25.29). Regarding patient survival, 68.1% and 35.3% of patients survived for >12 and >36 months, respectively. The three symptoms with the greatest relief were urine foam, poor appetite, and blurred vision. All 11 patients (7.6%) who experienced mild adverse reactions achieved remission. In conclusion, in MM patients with AKI, plasma-free plasmapheresis with 4% human ALB solution and bortezomib-based chemotherapy effectively alleviated light chain damage to kidney function while improving patient quality of life.

The International Association for the Study of Lung Cancer Thymic Epithelial Tumors Staging Project: Proposals for the N and the M Components for the Forthcoming (Ninth) Edition of the TNM Classification of Malignant Tumors.

INTRODUCTION: Stage classification is an important underpinning of management in patients with cancer and rests on a combination of three components-T for tumor extent, N for nodal involvement, and M for distant metastases. This article details the revision of the N and the M components of thymic epithelial tumors for the ninth edition of the TNM classification of malignant tumors proposed by the Thymic Domain of the International Association for the Study of Lung Cancer Staging and Prognostic Factors Committee. METHODS: The N and M components of the eighth edition staging system were verified by a large international collaborative data source through a data-driven analysis. A total of 9147 cases were included for analysis, including 7662 thymomas, 1345 thymic carcinomas, and 140 neuroendocrine thymic tumors. RESULTS: Lymph node involvement rates were 1.5% in thymomas and 17.6% and 27.7% in thymic carcinomas and neuroendocrine thymic tumors, respectively. Rates of lymph node metastasis were increasingly higher in tumors with higher T stage and higher-grade histologic type. Survival analysis validated the differences in the N and M categories proposed in the eighth edition staging system. Good discrimination in overall survival was detected among pathologic (p)N and pM categories in patients with thymoma and thymic carcinoma. CONCLUSIONS: No changes are proposed from the eighth edition for the N and M components. The proposed stage classification will provide a useful tool for management of the disease among the global thymic community.

The International Association for the Study of Lung Cancer Thymic Epithelial Tumors Staging Project: Proposal for a Stage Classification for the Forthcoming (Ninth) Edition of the TNM Classification of Malignant Tumors.

INTRODUCTION: A TNM-based system for all types of thymic epithelial tumors was introduced in the eighth edition of the TNM classification of thoracic malignancies. The Thymic Domain of the Staging and Prognostic Factors Committee of the International Association for the Study of Lung Cancer, composed of multispecialty international experts, was charged to develop proposals for the ninth edition. This article outlines the proposed definitions for the T, the N, and the M components and their combination into stage groups. METHODS: A large central database of 11,347 patients with thymic epithelial tumors was assembled thanks to the contribution of the major thymic organizations worldwide and analyses were carried out for the T, the N, and the M components and the stage groups. Overall survival was the outcome measure for patients with completely and incompletely resected tumors, and recurrence for those with complete resection. When the number of patients was sufficient, analyses were performed separately for thymomas, thymic carcinomas, and neuroendocrine thymic tumors. RESULTS: Tumor size is included in the T1 category as T1a (≤5cm) and T1b (>5 cm); the mediastinal pleura is dropped as a T descriptor; invasion of the lung or phrenic nerve is reclassified as T2 (instead of T3). No changes are proposed for the N and the M components from the eighth edition. The stage groups remain the same. CONCLUSIONS: The proposed changes for the ninth edition of the TNM classification set the stage for further progress in the future for these rare tumors.

Acquired von willebrand syndrome secondary to monoclonal gammopathy of undetermined significance: long-term remission after treatment with bortezomib.

Monoclonal gammopathy of undetermined significance (MGUS) is a plasma cell disorder that can precede the diagnosis of multiple myeloma. MGUS is characterized by the presence of a monoclonal paraprotein without evidence of multiple myeloma or other lymphoplasmacytic malignancies. Even though MGUS is an asymptomatic condition that does not require management strategies other than periodic follow-up to prevent complications, secondary nonmalignant diseases may arise, requiring control of the plasma cell clone. Acquired von Willebrand syndrome (AVWS) is a rare bleeding disorder that occurs in patients with no prior personal or family history of bleeding. It is associated with several other disorders, such as neoplasia, mainly hematological (including MGUS and other lymphoproliferative disorders), autoimmune, infectious and cardiac diseases. At diagnosis, patients usually present with cutaneous and mucosal bleeding, including gastrointestinal bleeding. Here, we report a case of a patient with MGUS who developed AVWS after one year of follow-up. The patient was refractory to glucocorticoids and cyclophosphamide and achieved remission only after monoclonal paraprotein was eradicated following treatment with bortezomib and dexamethasone. Our report sdemonstrates that, for refractory cases, eradication of the monoclonal paraprotein may be necessary to treat bleeding complications due to MGUS-associated AVWS.

Association between tamoxifen and tooth loss in women with breast cancer.

OBJECTIVES: Investigate the effect of tamoxifen on the occurrence of tooth loss (TL) in breast cancer (BC) survivors. METHODS: A cross-sectional study was conducted with 140 BC survivors using tamoxifen therapy. Sociodemographic, medical, and dental data were evaluated. TL was determined using the M component of the Decayed, Missing and Filled Teeth (DMFT) index. Logistic regression models were run to determine associations between the independent variables and outcome (TL). RESULTS: Mean TL was 12.96 (SD 8.88). Only three participants had lost no teeth and 10.7% were completely edentulous. Participants who used tamoxifen for more than 1 year had a higher mean missing teeth (13.99 vs. 10.45; P = 0.030). After the adjustments, the occurrence of more than 12 missing teeth was 2.75-fold higher among women who used tamoxifen for more than 1 year (95% CI: 1.06-7.12). Moreover, age over 65 years, referral for treatment by the public healthcare system, less use of dental services, xerostomia, and a lower occurrence of dental caries remained associated with the loss of more than 12 teeth. CONCLUSION: Longer use of tamoxifen was associated with greater tooth loss in breast cancer survivors. CLINICAL RELEVANCE: Based on estimates of the increase in cases of breast cancer, the prolonged use of tamoxifen for the treatment of this disease can exert an impact on oral health through the occurrence of tooth loss. These findings can contribute to the planning and implementation of oral health care and prevention strategies for such patients.

[Association between the presence of solid or micropapillary components and survival outcome in stage â A lung adenocarcinoma cases: a retrospective cohort study].

Objectives: To examine the influence of the proportion of pathological subtypes on the prognosis of stage ⅠA lung adenocarcinoma cases, and to explore the association between the presence/absence of solid or micropapillary (S/M) components and survival outcome. Methods: Totally 321 patients with stage ⅠA lung adenocarcinoma who received complete surgical resection at Department of Thoracic Surgery, Tongji University Affiliated Shanghai Pulmonary Hospital from January 2011 to December 2013 were retrospectively analyzed. There were 130 males and 191 females, aging 59(11) years (M(IQR)) (range: 55 to 66 years). The diagnostic value of the proportion of each pathological growth subtype on relapse-free survival (RFS) and overall survival (OS) were analyzed by using receiver operator characteristic curve. Patients were firstly divided into two groups according to the presence or absence of S/M components. And patients without S/M components were farther divided into two groups according to predominant growth pattern. There were three groups in total: with S/M components (group S/M+), without S/M components and lepidic growth pattern predominant (group S/M-LPA), without S/M components and papillary or acinar growth pattern predominant (group S/M-P/A). Kaplan-Meier method were used to draw the survival curves of the three groups, and Log-rank test were used to compare RFS and OS among the three groups. Cox proportional risk model was used to verify whether the presence of S/M components was a prognostic factor on RFS. Results: The proportion of S/M components had no diagnostic value for recurrence (solid: area under curve (AUC)=0.588, P=0.095; micropapillary: AUC=0.566, P=0.106) and death (AUC=0.589, P=0.104; AUC=0.607, P=0.056). The 5-year RFS rate of group S/M-LPA, S/M-P/A and S/M+ were 92.4%, 82.3% and 77.3%, respectively (all P<0.05), while the 5-year OS rate were 97.4%, 94.5% and 83.2%, respectively (all P<0.05). Multivariable analysis showed that the 3 groups were independent predictors of recurrence (S/M-P/A vs. S/M- LPA: HR=2.691, 95%CI: 1.249 to 5.799, P=0.011; S/M+ vs. S/M-LPA, HR=6.763, 95%CI: 3.050 to 14.996, P<0.01). Conclusions: The proportion of S/M components in stage ⅠA lung adenocarcinoma with complete resection cases did not affect survival outcome. New grouping method based on the presence or absence of S/M components were significantly associated with patient survival outcomes: S/M+ patients had the worst prognosis and S/M-LPA patients had the best prognosis.

Investigating the utility of saliva immunoglobulins for the detection of myeloma and using myeloma proteins to clarify partition between oral and systemic immunity.

OBJECTIVES: Myeloma is characterised by the presence of monoclonal immunoglobulin (M-protein) and the free light chain (FLC) in blood. We investigated whether these M-proteins and FLC are detectable in myeloma patients' saliva to evaluate its utility for non-invasive screening and monitoring of haematological malignancies. METHODS: A total of 57 patients with monoclonal gammopathy and 26 age-matched healthy participants provided paired serum and saliva samples for immunoglobulin characterisation and quantification. RESULTS: Myeloma patients had IgG or IgA M-protein levels ranging up to five times and FLC levels up to a thousand times normal levels of polyclonal immunoglobulins. Despite these highly elevated levels, only two IgG and no IgA M-proteins or FLC could be detected in paired saliva samples. Most patients had reduced levels of serum polyclonal immunoglobulins, but all had normal levels of salivary IgA. CONCLUSIONS: Immunoglobulin transfer from blood is not determined by levels in the systemic circulation and more likely dictated by periodontal inflammation and the integrity of the oral epithelium. Immunoglobulins secreted by bone marrow plasma cells do not substantially enter saliva, which represents a poor medium for myeloma diagnosis. These findings, along with normal salivary IgA levels despite systemic immunoparesis, support a strong partitioning of oral from systemic humoral immunity.

Monoclonal gammopathy in autoimmune diseases: Analysis and follow-up of 160 cases in a tertiary center in China.

Monoclonal gammopathy (MG) is common in autoimmune diseases (AID), but its progression to hematological neoplasm (HN) and the predictors for the progression are unclear. Patients diagnosed with AID and MG in our hospital from January 2010 to June 2017 were reviewed and followed. Cox proportional hazard regression analysis was applied. Of 160 patients with AID and MG, the most common AID was primary SjÓ§gren's syndrome (37, 23.1%). Thirty-nine (24.4%) patients developed HN during follow-up (median: 3.7 years, IQR: 0.3-5.5 years). The cumulative probability of HN progression was 21.8% at one year and 29.3% at six years after the finding of MG. High levels of monoclonal protein (> 14.35% of total serum protein) (HR 11.71, 95%CI: 5.37-25.54), significant weight loss (HR 6.24, 95%CI: 2.87-13.59), and reduction of other types of immunoglobulins (HR 3.02, 95%CI: 1.40-6.48) are independent risk indicators for HN whose presence warrants vigorous follow-up and monitoring.

Relationship of tumor load parameters before and after autologous stem cell transplantation with clinical prognosis in transplant-eligible patients with multiple myeloma: A retrospective analysis.

We retrospectively examined 57 patients with multiple myeloma who underwent autologous stem cell transplantation (ASCT) at our institution. A receiver-operating characteristic curve (ROC) analysis showed that the reduction rate of quantitative serum monoclonal protein (M-protein) before ASCT and the difference in involved and uninvolved free light chains (dFLC) 30 days after ASCT, respectively, had the greatest predictive value for all patients (area under the curve [AUC] 0.791 and 0.660, respectively). Based on the ROC curve-based cutoff values of tumor burden parameters, progression-free survival (PFS) in the high serum M-protein reduction (≥90 %) group was significantly better than that in the low serum M-protein reduction group (<90 %) (2-year PFS 79.5 % vs. 17.0 %, p < 0.001), but there were no significant differences in PFS between the low (<5.2 mg/L) and high (≥5.2 mg/L) dFLC groups (2-year PFS, 72.0 % vs. 46.0 %; p = 0.149). A multivariate analysis identified the reduction in serum M-protein as an independent predictive factor before ASCT for PFS (hazard ratio [HR] 0.287, p = 0.022) and high dFLC on day 30 after ASCT for PFS (HR 3.902, p = 0.040). These results demonstrate that a good prognosis can be expected with a reduction of serum M-protein before and after ASCT.

Population pharmacokinetic and exposure-response analyses of elotuzumab plus pomalidomide and dexamethasone for relapsed and refractory multiple myeloma.

PURPOSE: Elotuzumab plus pomalidomide/dexamethasone (E-Pd) demonstrated efficacy and safety in relapsed and refractory multiple myeloma (RRMM). The clinical pharmacology of elotuzumab [± lenalidomide/dexamethasone (Ld)] was characterized previously. These analyses describe elotuzumab population pharmacokinetics (PPK), the effect of Pd, and assess elotuzumab exposure-response relationships for efficacy and safety in patients with RRMM. METHODS: A previously established PPK model was updated with E-Pd data from the phase 2 ELOQUENT-3 study (NCT02654132). The dataset included 8180 serum concentrations from 440 patients with RRMM from 5 clinical trials. Elotuzumab PK parameter estimates were used to generate individual daily time-varying average concentrations (daily Cavg) for multi-variable time-to-event exposure-response analyses of progression-free survival (PFS) and time to the first occurrence of grade 3 + adverse events (AEs) in RRMM. RESULTS: Elotuzumab PK were well-described by a two-compartment model with parallel linear and Michaelis-Menten elimination from the central compartment (Vmax) and non-renewable target-mediated elimination from the peripheral compartment (Kint). Co-administration with Pd resulted in a 19% and 51% decrease in elotuzumab linear clearance and Kint, respectively, versus Ld; steady-state exposures were similar. Vmax increased with increasing serum M-protein. Hazard ratios (95% confidence intervals) for daily Cavg were 0.9983 (0.9969-0.9997) and 0.9981 (0.9964-0.9998) for PFS and grade 3 + AEs, respectively. CONCLUSIONS: The PPK model adequately described the data and was appropriate for determining exposures for exposure-response analyses. There were no clinically relevant differences in elotuzumab exposures between Pd and Ld backbones. In ELOQUENT-3, increasing elotuzumab daily Cavg prolonged PFS without increasing grade 3 + AEs.

MALDI-TOF mass spectrometry can distinguish immunofixation bands of the same isotype as monoclonal or biclonal proteins.

BACKGROUND: Plasma cell disorders (PCDs) are typically characterized by excessive production of a single immunoglobulin, defined as a monoclonal protein (M-protein). Some patients have more than one identifiable M-protein, termed biclonal. Traditional immunofixation electrophoresis (IFE) cannot distinguish if two bands of the same isotype represent biclonal proteins or M-proteins with some other feature. A novel assay using immunoenrichment coupled to matrix-assisted laser desorption ionization time-of-flight mass-spectrometry (Mass-Fix) was applied to determine whether two bands of the same isotype represented (1) monomers and dimers of a single M-protein, (2) an M-protein plus a therapeutic monoclonal antibody (t-mAb), (3) an M-protein with light chain glycosylation, or (4) two distinct biclonal M-proteins. METHODS: Patient samples with two bands of the same isotype identified by IFE were enriched using nanobodies against IgG, IgA, IgM, or κ and λ light chains then analyzed by Mass-Fix. Light chain masses were used to differentiate IgGκ M-proteins from t-mAbs. Mass differences between peaks were calculated to identify N-glycosylation or matrix adducts. High-resolution mass spectrometry was used as a comparator method in a subset of samples. RESULTS: Eighty-one residual samples were collected. For IgA, 93% (n = 25) were identified as monoclonal. For IgG, 67% (n = 24) were monoclonal, and 33% (n = 12) were truly biclonal. Among the monoclonal IgGs, the second band represented a glycosylated form for 21% (n = 5), while 33% (n = 8) had masses consistent with a t-mAb. 44% (n = 8) of IgM samples were biclonal, and 56% (n = 10) were monoclonal, of which one was glycosylated. CONCLUSIONS: We demonstrate the utility of mass spectrometry in the characterization of multiple IFE bands of the same isotype. Improved reporting accuracy of M-proteins is useful for monitoring of patients with PCDs.

Solution structures of human myeloma IgG3 antibody reveal extended Fab and Fc regions relative to the other IgG subclasses.

Human immunoglobulin G subclass 3 (IgG3) possesses a uniquely long hinge region that separates its Fab antigen-binding and Fc receptor-binding regions. Owing to this hinge length, the molecular structure of full-length IgG3 remains elusive, and the role of the two conserved Fc glycosylation sites are unknown. To address these issues, we subjected glycosylated and deglycosylated human myeloma IgG3 to multidisciplinary solution structure studies. Using analytical ultracentrifugation, the elongated structure of IgG3 was determined from the reduced sedimentation coefficients s020,w of 5.82 to 6.29 S for both glycosylated and deglycosylated IgG3. X-ray and neutron scattering showed that the Guinier RG values were 6.95 nm for glycosylated IgG3 and were unchanged after deglycosylation, again indicating an elongated structure. The distance distribution function P(r) showed a maximum length of 25 to 28 nm and three distinct maxima. The molecular structure of IgG3 was determined using atomistic modeling based on molecular dynamics simulations of the IgG3 hinge and Monte Carlo simulations to identify physically realistic arrangements of the Fab and Fc regions. This resulted in libraries containing 135,135 and 73,905 glycosylated and deglycosylated IgG3 structures, respectively. Comparisons with the X-ray and neutron scattering curves gave 100 best-fit models for each form of IgG3 that accounted for the experimental scattering curves. These models revealed the first molecular structures for full-length IgG3. The structures exhibited relatively restricted Fab and Fc conformations joined by an extended semirigid hinge, which explains the potent effector functions of IgG3 relative to the other subclasses IgG1, IgG2, and IgG4.

Cyclophosphamide plus etoposide is a safe and effective mobilization regimen in patients with multiple myeloma.

High-dose chemotherapy followed by autologous stem cell transplantation is a major component in the treatment of patients with multiple myeloma. As a prerequisite, the successful collection of a sufficient number of viable peripheral blood hematopoietic CD34+ cells is critical. A common standard protocol for mobilization is currently not defined and critically discussed especially in German-speaking Europe. In times of the Covid-19 pandemic, safe and effective strategies have to be chosen to minimize hospitalization times and severe courses. In this single-center retrospective analysis, safety and efficacy of cyclophosphamide plus etoposide (CE) and growth-factor support (n = 33) was compared to cyclophosphamide mono treatment and growth-factor support (n = 49) in 82 patients with multiple myeloma at first diagnosis. CE was superior to cyclophosphamide mono with a significantly higher number of collected CD34+ cells (15.46 × 106 CD34+ cells/kg vs. 9.92 × 106 CD34+ cells/kg), significantly faster engraftment of granulocytes after stem cell transplantation (day 10.5 vs. day 11.6), shorter duration of the inpatient stay (17.47 days vs. 19.16 days) and significantly less transfusions (8.82 % vs. 30.61 % patients receiving transfusions). The safety profile was comparable in both groups and in line with published data. We conclude that CE is a safe and highly effective mobilization protocol in patients with multiple myeloma at first diagnosis and appears to be superior to the commonly used cyclophosphamide mono regimen.

Application of Capillary Electrophoresis in Monoclonal Gammopathies and the Cutoff Value of Monoclonal Protein in Differential Diagnosis of Multiple Myeloma and Other Monoclonal Gammopathies.

OBJECTIVE: Monoclonal protein (MP) exists in various diseases, and capillary electrophoresis (CE) has been widely used to detect MP. However, there is not much research on the application value of MP in the differential diagnosis of monoclonal gammopathies. This study aimed to explore MP's cutoff value for the differential diagnosis of multiple myeloma (MM) and other monoclonal gammopathies (MGs). METHODS: A retrospective analysis of 8167 cases was conducted. Serum MP was detected by CE, and the patients' clinical information was collected from the clinical database of our hospital. RESULTS: 985 cases had MP with high peaks, and 91.1% were diagnosed with malignant diseases. The MP showed small peaks in 471 cases, and only 24.4% were diagnosed with malignant diseases. Among the MPs, the IgG-κ type was the most common type, followed by the IgG-λ, IgA-κ, IgA-λ, free λ light chain, IgM-κ, free κ light chain, double clone, and IgM-λ types. Differences in the MP of the IgG, IgA, IgM, and FLC types between the MM group and MGUS group were statistically different (P<0.01). The MP of the IgG, IgA, and FLC types showed clear specificity and sensitivity in discriminating MM from other monoclonal gammopathies in ROC curve analysis. Serum IgM had statistical significance in the differential diagnosis between WM and other MGs (P<0.01). However, there was no statistical significance in the differential diagnosis between MM and other MGs (P=0.140). The cutoff values of the MP of the IgG, IgA, and FLC types were >18.67g/L, >13.86g/L, and >10.15g/L, respectively, for the differential diagnosis of MM and other MGs. The cutoff value of the MP of IgM for the WM diagnosis was >37.75 g/L. CONCLUSION: CE has good clinical application value in the diagnosis of monoclonal gammopathies, and MP can be used in the differential diagnosis of MM and other monoclonal gammopathies.

PK/PD modeling analysis for dosing regimen selection of isatuximab as single agent and in combination therapy in patients with multiple myeloma.

This analysis describes the pharmacokinetic/pharmacodynamic (PK/PD) modeling framework that supported selection of the isatuximab (anti-CD38 monoclonal antibody) dosing regimen alongside its early clinical development in patients with relapsed/refractory multiple myeloma (RRMM). The PK/PD mathematical model characterized the variations of patient serum M-protein concentrations, the primary marker of tumor burden in multiple myeloma (MM). Three separate PK/PD models were built sequentially as data became available from phase I clinical trials. The primary PK/PD analysis was initiated using monotherapy phase I study data (n = 122), followed by analysis of data collected from phase Ib combination studies with lenalidomide and dexamethasone (Rd, n = 40) and then with pomalidomide and dexamethasone (Pd, n = 31). Using the PK/PD model, abnormal "myeloma" protein (M-protein) profiles under different isatuximab dosing regimens were simulated. Overall, simulations revealed that regimens which included a loading period of four weekly administrations followed by administration every 2 weeks thereafter (QW4-Q2W), reduced M-protein levels more than a Q2W regimen without a loading period. For isatuximab monotherapy, a 20 mg/kg dose induced greater reduction in serum M-protein levels compared with doses equal or lower than 10 mg/kg. For isatuximab in combination with either Rd or Pd, simulations yielded no substantial benefit in terms of M-protein reduction between isatuximab 10 mg/kg and 20 mg/kg. These PK/PD analyses supported the use of isatuximab 10 mg/kg QW4-Q2W in combination with Pd in the phase III trial.

Subgroup analysis of ICARIA-MM study in relapsed/refractory multiple myeloma patients with high-risk cytogenetics.

Treatment benefit in multiple myeloma (MM) patients with high-risk cytogenetics remains suboptimal. The phase 3 ICARIA-MM trial (NCT02990338) showed that isatuximab plus pomalidomide-dexamethasone prolongs median progression-free survival (mPFS) in patients with relapsed/refractory MM (RRMM). This subgroup analysis of ICARIA-MM compared the benefit of isatuximab in high-risk [defined by the presence of del(17p), t(4;14) or t(14;16)] versus standard-risk patients. The efficacy of isatuximab in patients with gain(1q21) abnormality was also assessed in a retrospective subgroup analysis. In ICARIA-MM, 307 patients received isatuximab-pomalidomide-dexamethasone (n = 154) or pomalidomide-dexamethasone (n = 153). Isatuximab (10 mg/kg intravenously) was given weekly in the first 28-day cycle, and every other week thereafter. Standard pomalidomide-dexamethasone doses were given. Isatuximab-pomalidomide-dexamethasone improved mPFS (7·5 vs 3·7 months; HR, 0·66; 95% CI, 0·33-1·28) and overall response rate (ORR, 50·0% vs 16·7%) in high-risk patients. In patients with isolated gain(1q21), isatuximab addition improved mPFS (11·2 vs 4·6 months; HR, 0·50; 95% CI, 0·28-0·88) and ORR (53·6% vs 27·6%). More grade ≥3 adverse events occurred in high-risk patients receiving isatuximab (95·7%) versus the control group (67·6%); however, isatuximab did not increase events leading to discontinuation or treatment-related mortality. Isatuximab-pomalidomide-dexamethasone provides a consistent benefit over pomalidomide-dexamethasone treatment in RRMM patients regardless of cytogenetic risk.

Clearing drug interferences in myeloma treatment using mass spectrometry.

OBJECTIVE: To explore the possibility of using a combination of a rapid MALDI-TOF-MS method (Mass-Fix) in conjunction with higher resolution LC-ESI-QTOF-MS (miRAMM) measurements to discriminate the IgG kappa M-protein from daratumumab, elotuzumab and isatuximab in myeloma patients. DESIGN & METHODS: 86 patients with an IgG kappa M-protein were spiked with therapeutic levels of the drugs and examined by Mass-Fix and miRAMM to establish the percent of cases that could be resolved by each method. The method was then applied to 21 samples from patients receiving one of the drugs. RESULTS: Mass-Fix was capable of resolving the t-mAb from M-protein for 87 percent of the spiked samples. For the cases unresolved by Mass-Fix, miRAMM was capable of resolving the remaining drug interferences. The 21 IgG kappa myeloma patients that were receiving the drugs were all resolved by Mass-Fix. CONCLUSION: This proposed algorithm allows use of a clinical available assay (Mass-Fix) while maximizing the number of cases that can accurately resolve the t-mAb from the M-protein.